Contactor cover interlock



March 29, 1966 E PLATZ ETAL 3,243,535

CONTAGTOR COVER INTERLO GK E; T. PLATZ ETAL 3,243,535

' coNTAcToR COVER INTERLocK March 29, 1966 Filed Jan. 27, 1964 2Sheets-Sheet 2 United States Patent O 3,243,535 CQNTACTGR COVERINTERLOCK Elwood T. Platz, Grosse Pointe Farms, Bernard Di Margo,

Lincoln Park, and Robert L. Hickey, St. Clair Shores,

Mich., assignors to I-T-E Circuit Breaker Company,

Philadelphia, Pa., a corporation of Pennsylvania Filed Jan. 27, 1964,SeraNo. 340,449 8 Claims. (Cl. 20D-50) This invention relates tocontactors in general and more particularly to novel interlock means forpreventing clossure of the contact-or when the contact area cover 1sremoved.

The copending U.S. patent application Serial No. 189,915, filed April24, 1962, entitled Electrical Device, with Cataldo et al. as invent-ors,and assigned to the assignee of the instant invention, describes amultiphase contactor which with only minor modification, may beprovide-d with interlock means to prevent contact closure when thecontact cover is removed.

The contactor of the aforesaid application includes cooperatingstationary and movable contacts, a carrier for the movable contacts, amagnetic operating means for operating the cooperating contacts intoengagement, a removable contact area cover and clip means f-ormaintaining the cover latched in closed position. It has been founddesirable, and quite often, necessary, to prevent contact closing unlessthan cover is in fully closed position.

This is conveniently accomplished in one embodiment of this invention byproviding cover clamp means which when operated to cover releasingposition are disposed in blocking relation with respect to the movablecontact carrier thereby preventing closing of the contacts.

In another embodiment of this invention a member carried by thecontactor frame is biased toward position to interfere with the contactcarrier and automatically moves to this position when the cover is notclosed. Closing of the cover moves the member clear of the contactcarrier to permit closing of the contacts.

Accordingly, a primary 4object of the instant invention is to providenovel means to prevent closuring of a contactor when its contact area isuncovered.

Another 4object is to provide means of this type including a memberwhich is biased to position for interfering with the movable contactcarrier.

Still another object is to provide means of this type in which themember is also served as clamping means for the contact area cover.

A further object is to provide a means for this type in which thebiasing means is too strong to be overcome by the force of the magneticclosing means.

These as well as lother objects of this invention will become readilyapparent after reading the following description of the accompanyingdrawings in which:

FIGURE 1 is a side elevation of a contactor including `contact interlockmeans constructed in accordance with the teachings of the instantinvention.

FIGURE 2 is a plan view of the contactor of FIG- URE 1 with portions ofthe cover broken away to reveal portions of the contact structure.

FIGURE 3 is an enlarged fragmentary cross-section taken through line 3-3of FIGURE 4 looking in the direction of arrows 3-3.

FIGURE 4 is a cross-section taken through line 4-4 of FIGURE 3 lookingin the direction of arrows 4 4.

FIGURES 5 and 6 are views similar to FIGURES 3 and 4, respectively,illustrating another embodiment of this invention.

FIGURES 7 and 8 are views similar to FIGURE 3, illustrating stillanother embodiment of this invention. In FIGURE 7 the contactor isinterlocked open while 3,243,535 Patented Mar. 29, 1966l ice in FIGURE 8the contactor cover is closed thereby operating the interlock means topermit contact closing.

For the sake of clarity all contacts and operating mechanisms have beenomitted from FIGURES 3 through 8.

Now referring to the figures and more particularly to FIGURES 1 through4. Contacter 10 is provided with a contact structure, contact operatingmechanism, Contact support means and contact cover means as described inthe aforesaid copending application Serial No. 189,915.

Briefly, contactor 10 includes molded base 11 wherein electromagneticcontact operating means (not shown) is -disposed with the operating coilof the latter having its terminals 12, 13 `disposed externally `of base11. Stationary contact support plate 14, carrying guide studs 15, ismounted at the upper end of base 11 by means of screws 16, 17 whichengage line and load terminals 18, 19, respectively. In FIGURE 2 theline terminals of the different poles are ydesignated 18A, 18B and 18Cwhile the load terminals are designated 19A, 19B and 19C. Screws 16electrically connect individual stationary contacts 21 to each lineterminal 18 while screw 17 electrically connect individual stationarycontacts 22 to each load terminal 19. Stationary contacts 21, 22 aremounted on the top side of support plate 14.

Movable contact carrier 23 is mounted below support plate 14 forreciprocating movement guided by studs 15. Downward movement is causedby the actuation of the operating coil connected across terminals 12, 13while upward movement is caused by biasing springs 26, coiled about eachstud 15, when the operating coil is deenergized.

Clips 29A, 29B mount bridging contacts 30A, 30B, respectively, to theupper ends of extensions, from carrier 23, which project lthroughapertures in support plate 14. Naturally, the third pole is providedwith a bridging contact 30C (not shown) similarly mounted.

Bridging contacts 30A, 30B, 30C are mounted above stationary contacts21, 22 and are spaced therefrom when carrier 23 is in the raisedposition shown (when contactor 10 is open. When carrier 23 movesdownward, the bridging contacts 30A, 30B, 30C each engage a set ofstationary contacts 21, 22 thereby closing the circuit between the lineand load terminals 18, 19 of the particular phase.

Removable cover 35, positioned above support plate 14, encloses the areawherein the contacts 21, 22, 30 are disposed. Clamps 40, disposed -onopposite sides of base 11, latch cover 35, in closed position. Since theconstructions of both clips 40, their mountings and their engagementwith cover 35 and carrier 23 are identical only one of them will bedescribed with particular reference to FIGURES 3 and 4.

With clamp 40 in the solid line position of FIGURE 4 inward hook-shapedoffset 49a thereof is disposed within depression 35a in the outersurface of cover 35 so that cover 35 is latched closed. In order torelease cover 35 for removal thereof tab 40b at the inner end of offset40a is grasped and moved to the right with respect to FIG- URE 4. Thispivots clamp 40 clockwise about wire spring 45 as a center. Wire 45extends through the U- turned portion 40e at the end of clamp 40 remotefrom tab 4Gb. The ends of wire spring 45 are disposed within recess 44,in support 14, open at its lower end. Sloping surfaces 43 of support 14is so shaped and positioned relative to the `bearing surfaces `definingrecess 44 that spring 45 is always loaded and as the outer portions oftab 4Gb engage surfaces 43 spring 45 moves-clamp 40 to blockingposi-tion shown in phantom in FIGURE 4.

In this position clamp portion 40a is disposed below the inwardprojection 23a at the upper end of upward extension 23b of carrier 23.In this position of clamp 40, portion 40a block downward or contactclosing movement of carrier 23. Should contact closing be required whilecover 35 is off the interlock function may be defeated by moving bothclamps 40 to latching positio-n so that Iportions 40a will no longer bein the paths of carrier projections 23a.

In the embodiment of FIGURES 5 and 6 clamp 140 is provided withhook-like portion 140a yfor cover latching and tab 14019 for cover latchrelease. The central portion of clamp 140 is provided with U-shapedportions which embrace wire spring 145 the ends of which are disposedWithin recesses 146 of support plate 114. Clamp 140 is provided with aninterlock portion in the form of projection 140e having inturned tip140i. Projection 140e extends downward into carrier recess 151.

When cover 135 is unlatched spring 145 in cooperation with slopingsurfaces 143 guide cla-mp 140 in a clockwise direction with respect toFIGURE 6 to a position wherein extension tip 1401c is disposed withincarrier undercut 152. In this position of clamp 140, tip 140f performsthe interlock function by blocking downward movement of carrier 123. Theinterlock function of this second embodiment is defeatable in the samemanner as in the embodiment of FIGURE 1-4.

In the embodiment of FIGURES 7 and 8 stud 250 eX- tends through alignedaperture-s 21401, 223a in stationary contact support 214 and movablecontact carrier 223, respectively. The lower enlarged head 250a of stud250 is disposed below carrier 223 while the upper enlarged head 250k isdisposed above support 214. Coil spring 251 is -mounted upon stud 250bearing against upper head 25017 and support 214.

With cover 235 open as in FIGURE 7 lower head 25001 engages carrier 223Iand spring 251 biases carrier 223 upward to the open position of thecontactor. Spring 251 and opening springs 26 combined exert a greaterforce than the closing magnet so that with the elements in theirpositions of `FIGURE 7 the contactor cannot be closed.

When cover 235 is in the closed position of FIGURE 8 head -250b andcompressed spring 251 are disposed within cover recess 235er. Theengagement of heardl 250b by cover 235 has moved stud 250 downward sothat lower head 250a is considerably below carrier 223. In this positionof head 250a carrier 223 may be moved downward. Hence, the contactor maybe closed.

In this embodiment the interlock may be defeated manually by moving stud250 downward. Then the contactor may be closed. While only a single studand spring have been described, it should Ibe understood that when aplurality of these elements are present that it is the combined springforces which must be overcome by the electromagnetic closing means.

Although there has been described a preferred embodiment of this novelinvention, many variations and modifications will now be apparent tothose skilled in the art. Therefore, this invention is to be limited,not by the specific disclosure herein, but only by the appending claims.

The embodiments of the invention in which as eX- clusive privilege orproperty is claimed are dened as follows.

1. A device of the cla-ss described including stationary c-ontact means,movable contact means operable into and out of engagement with saidstationary contact means, a stationary support means to vwhich saidstationary contact means is mounted, a carrier means to which saidmovable contact means is mounted, means for guiding movement of saidcarrier means lalong a predetermined path relative to said support meansbetween a contact closed and a contact open position, operable covermeans cooperating with portions of said support means to enclose saidstationary -and said movable contact means, interlock means including amember mounted to said support means and movable between a rst and -asecond position, said member when in said rst position being clear ofsaid path Iand when in said second position having a portion thereof insaid path, said interlock means also including biasing meansautomatically operating said member to said second position when saidcover means is open thereby blocking movement of said `carrier means tosaid contact closed position, said member When in Said first positionengages said cover means when said cover lmeans is closed to clamp saidcover means in this position with said biasing means contributing toclamping action of said member.

2. A device as set forth in claim 1 in which said member is pivotallymounted at one end thereof, said portion of said member being positionedat the other end of said member.

3. A device as set forth in claim 2 in which there is a deflectedstraight wire spring constituting said biasing means and alsoconstituting a pivotal axis for said member.

4. A device as set forth in claim 1 in Vwhich said member is pivotallymounted at a point intermediate the ends thereof, said portion of saidmember being positioned at one end of said member, said member includinganother portion at its other end which acts to clamp said cover means inclosed position.

'5. A device as set forth in claim 4 in which there is a deectedstraight wire spring constituting said biasing means and alsoconstituting a pivotal axis for said member.

6. A device of the class described including stationary contact means,movable conta-ct means operable into and out of engagement with saidstationary contact means, la stationary support means to which saidstationary contact means is mounted, a carrier means to which saidmovable contact means is mounted, means for guiding movement of saidcarrier means along a predetermined path relative to said support means`between a contact closed and a contact open position, operable covermeans cooper-ating with portions of said support means to enclose saidstationary and said movable contact means, interlock means including 4amember mounted to said support means and movable between la first and asecond position, said member when in said first position being clear ofsaid path and when in said second position having a portion thereof insaid path, said interlock means also including Ibiasing meansautomatically operating said member to said second position when saidcover means is open thereby blocking movement of said carrier means tosaid contact closed position, said Icover means upon placement thereofin closed position engaging said member and operates same to said rstposition, said device also including -an electromagnetic loperatingmeans for closing said contact means and a spring means for opening saidcontact means when said operating means is deenergized, said operatingmeans when energizedbeing incapable of exerting a for-ce capable ofovercoming the combined forces of said spring means and said biasingmeans.

7. A device of the class described including stationary Contact means,movable contact means operable into and out of engagement with saidstationary contact means, a stationary .support means to which saidstationary contact means is mounted, ya carrier means to which saidmovable contact -means is mounted, means for guiding move-ment of saidcarrier means along a predetermined path relative to said support meansbetween a contact closed and a contact open position, operable covermeans cooperating with portions of said support means to enclose saidstationary and said movable contact means, interlock means including amember mounted to said support means and movable between a first and asecond position, said member when in said rst position being clear ofsaid path and when in said second position having a portion thereof insaid path, said interlock means also including biasing meansautomatically operating said 3,243,535 5 6 member to said secondposition when said cover is open References Cited by the Examinerthereby blocking movement of said carrier means to said FOREIGN PATENTS`contact closed position, said cover means upon placement thereof inclosed position engaging said member and op- 7341845 8/1955 GreatBn'tamerates same to said irst position, said member comprising 5 anelongated element slidably mounted for movement KATHLEEN H' CLAFF YPrimary Examiner' along its longitudinal axis. M. GINSBURG, AssistantExaminer.

8. A device as set forth in claim 7 in which the biasing means is acoiled member mounted upon said elongated element. 10

1. A DEVICE OF THE CLASS DESCRIBED INCLUDING STATIONARY CONTACT MEANS,MOVABLE CONTACT MEANS OPERABLE INTO AND OUT OF ENGAGEMENT WITH SAIDSTATIONARY CONTACT MEANS, A STATIONARY SUPPORT MEANS TO WHICH SAIDSTATIONARY CONTACT MEANS IS MOUNTED, A CARRIER MEANS TO WHICH SAIDMOVABLE CONTACT MEANS IS MOUNTED, MEANS FOR GUIDING MOVEMENT OF SAIDCARRIER MEANS ALONG A PREDETERMINED PATH RELATIVE TO SAID SUPPORT MEANSBETWEEN A CONTACT CLOSED AND A CONTACT OPEN POSITION, OPERABLE COVERMEANS COOPERATING WITH PORTIONS OF SAID SUPPORT MEANS TO ENCLOSE SAIDSTATIONARY AND SAID MOVABLE CONTACT MEANS, INTERLOCK MEANS INCLUDING AMEMBER MOUNTED TO SAID SUPPORT MEANS AND MOVABLE BETWEEN A FIRST AND ASECOND